1. Field of the Invention
This invention relates to a dental rubber dam frame and more particularly to a dental rubber dam frame having improved retraction and stability which also allows for increased patient comfort and safety.
2. Background
The rubber dam is an elastic membrane used in dentistry to isolate an intra-oral operative site that is to be worked on by the dentist. It is used at the operative site in order to help the dentist control moisture when the procedure requires a dry environment, prevent the ingestion and aspiration of foreign objects by the patient, and optimize the overall quality of dental treatment during the procedure. The rubber dam is first secured at the site of operation and then stretched over a framework, which is generally exterior to the mouth of the patient. Early designs of rubber dam frames typically have a “U” shaped frame member that is positioned over the patient's face so that the open portion of the “U” faces upward toward the patient's nose. The rubber dam membrane is stretched over the frame and subsequently secured to the frame with projections or nibs spaced at intervals around the periphery of the frame. In theory, the reciprocal stretching of the membrane stabilizes the frame in relation to the patient's oral cavity.
There are a number of shortcomings of standard prior art frames with this “U” shaped design, with one common problem being the potential liability of the open ends, or legs, of the frame poking the patient in the eye during application of the dam or in the course of treatment. One of the early rubber dam frame designs patented, U.S. Pat. No. 682,308 by L. A. Young on Sep. 10, 1901, entitled Rubber Dam Holder, disclosed a frame having the now standard “U” shape. The U-shaped frame satisfied the general requirements of a rubber dam frame and is the basic design still used today. However, the U-shape frame comprised open, unprotected vertical legs, which is believed to have caused injuries to patients' eyes and faces over the course of the 20th Century. Therefore an improved rubber dam frame, which addressed this issue of potential eye damaging accidents, was designed and patented Oct. 22, 1968 by Richard S. McConville, U.S. Pat. No. 3,406,452, entitled Dental Rubber Dam Frame. Although the inventor retained the “U” shaped configuration of the frame one significant feature of this new frame was the addition of ¼ inch round balls or spheres to the ends of the vertical stems or legs of the frame. These large rounded contour balls or spheres, covered the sharp ends of the legs, such that if there was accidental contact with a patient's eye, permanent damage would be avoided and trauma minimized. This improvement was considered useful and this type of frame gained market share in competing with the original design of the '308 frame and is still used in practice by dentists today.
FIG. 4 is an illustration of a “U” shaped frame of the '452 patent design, with a conventional rubber dam stretched over the framework. The figure also illustrates the dentist's inability to achieve a uniform retraction of the rubber dam membrane when using this type of rubber dam frame. As seen in the figure the frame does not contain an upper element and therefore there is a subsequent lack of retraction of the upper lip, with the slumping of the rubber dam adjacent to the upper front teeth. The illustration also shows excess rubber dam material covering the patient's nostrils, which is known to obstruct breathing and cause discomfort to the patient. Further, FIG. 4 depicts a lack of sufficient number of retraction nibs on the lower transverse horizontal member, which subsequently creates an insufficient retraction of the lower lip. The overall resultant effect of the “U” shaped frames is that they give inadequate support to and retraction of both the patient's upper lip and lower lip, due in part because they lack an upper transverse member and because the scarcity of locations where the rubber dam attached to the frames. A further problem exists with the early designs of rubber dam frames in that the recently invented general field isolation rubber dams are known to need even more labial retraction to provide the required stability in the patients mouth.
Other frames have been introduced to the field of dentistry that are circumferential in design, but these have also lacked a retraction mechanism for adequately retracting and distributing the vector forces required for rubber dam retraction. One such circumferential frame, having the characteristics of a rounded square, was known as the Nygaard-Ostby frame. The Nygaard-Ostby frame provides an upper member that is absent in the other frames, however it has extremely large, sharp projections that engage the rubber dam membrane in order to anchor the rubber dam to the frame. One large, sharp projection is allocated to the upper member, and is placed squarely in the center of the frame, where it is most likely to line up with and injure the patient's nasal septum. This frame, with large, sharp projections radiating in all directions is a menacing looking device, which raises questions about the safety and comfort of the patient during use of the device. While this single rubber dam attachment on an upper member may afford some increased retraction of the upper lip, the design provides this at the expense of interfering with and very likely injuring the patient in the process.
Another shortcoming of the frames found in dentistry, whether they are of the “U” shaped variety or the circumferential Nygaard-Ostby design, is that the frames are designed so that any excess stretched rubber dam membrane in the nasal area flaps over the patient's nose, obstructing breathing and often causing the patient to feel claustrophobic. The patient undergoing dental treatment is already in a heightened state of anxiety or stress, and does not need additional stressors added to the experience of the dental treatment. Currently none of the rubber dam frames available for use in dentistry address the problems caused by having excess rubber dam material in the nasal area, which may lead to obstruction of the patient's breathing and further to feelings of smothering or claustrophobia.
To date the field of dentistry lacks rubber dam frames with design features that adequately support the use of general field isolation rubber dams because as stated above, until recently in dentistry there had not been a thorough systematic design and development of general field isolation rubber dams. The development and introduction of new general field isolation rubber dams and newly designed conventional application rubber dams has evolved from an extensive analysis of the vector forces of stretched elastic rubber dam membranes and their interaction with oral anatomical structures. Therefore it follows that a newly designed rubber dam frame is needed to complement and enhance the function of the newly introduced general field isolation and conventional rubber dams. Beyond the benefits of the improved rubber dam frames for the newly introduced rubber dams, the new frames also improve the retraction, stability, safety, and comfort of existing conventional rubber dam applications as well. The need exists for a rubber dam frame capable of overcoming the shortcomings of the current rubber dam frames while providing improved support and retraction for both the new general field isolation rubber dams and the conventional isolation rubber dams. The improved frames would improve rubber dam applications by taking into account the vector forces of the stretched elastic rubber dam membrane and the way in which the forces are used in order to achieve optimal isolation of the operative site. The frames should effectively eliminate all pointed or protruding elements which may accidentally cause eye injury or injury to the face, allow attachment of the rubber dam membrane to the frame in a complete circumferential manner, to increase retraction and support of the patients lips, and increase support, retention, and retraction for the new general field isolation rubber dams by distributing the tensile forces of the stretched membrane, and further manage excess rubber dam membrane to prevent nasal obstruction and discomfort to the patient.